@mixin margin-bottom($key) {
    margin-bottom: map-get($map, $key);
}

@media (max-width: 480px) {
.bd-examples {
margin-right: -0.75rem;
margin-left: -0.75rem;
}

.bd-examples > [class^='col-'] {
    padding-right: 0.75rem;
    padding-left: 0.75rem;
}
}

.mb4 {
@include margin-bottom(4);
}
